asus mg279q

His y'all I'm crashing while gaming. Some say it's my psu most likely. Thing is, I only crash when I have my gpu (R9 390) connected to my Asus mg279q either via mini DP-DP port or HDMI. It crashes on HDMI as well you see, but when I hook my PC to my television via HDMI and game, it runs like a...